POSH encapsulates the best practices of using semantic HTML to author web pages. Semantic HTML is the subset of HTML 4.01 (or XHTML 1.0) elements and attributes that are semantic rather than presentational. The best way to learn and understand POSH is to do it. Pick a page on your web site to begin with, and apply the POSH Checklist to it. Continue with the POSH Process. Read POSH Resources to learn more about POSH.